Interior Design of a Living Room – SketchUp and V-RayMario Goleš is a very talented interior designer and 3D architectural visualizer, currently working and based in Zagreb, Croatia. He has kindly offered to share this detailed workflow in the production of an interior living room design, in which he uses SketchUp for the model and V-Ray for the render. There is a lot of good solid information here with many tips to suit all levels of experience. This tutorial can only be described as the ‘How and Why’ of good rendering. Some working knowledge of SketchUp and V-Ray is needed to follow and understand this tutorial. In this tutorial, I will explain my workflow in a project I called “Interior Design of a Living Room”. As you all know, making such a project requires a certain amount of knowledge and experience in the CG industry, as well as in interior design, so I will cover only what I believe people commonly have most trouble with. This will include texturing, lighting and the rendering processes. First, I want you to notice that this project have been created in SketchUp. The rendering engine I used for the final visualization was V-Ray. I also using predefined materials (.vismat files); I often use these in my projects, downloaded from “Chaos Group”, “Visual Dynamics” and “Flying Architecture” web sites. I am sure with a little patience you could find some more web sites, from where you can download “.vismat” files. I have also used several 3D models downloaded from the 3D Warehouse. The others I just modeled by myself. For lighting techniques, I used HDRI images that you can also find on the Internet. Some of them are free to download but if you’re needs are of a more professional nature (your professional work), I suggest you invest in buying quality texture images and even 3D models. Before I explain my workflow, I just want to mention a few important points that I believe are crucial in achieving a good 3D render, and are far more important than just following a workflow explanation.
- Many people ask me about “V-Ray” options (.visopt file), and how I set up the rendering parameters, expecting that if they do the same they will get a realistic image. You have to understand that any rendering engine, including “V-Ray”, does nothing else but what is based on your parameters setup. It calculates how light travels through your scene and it bounces from different surfaces, in order to potentially get a realistic image. Due to this, almost all its parameters are about setting different light calculation methods. Therefore, if you set its parameters correctly you will get nothing else but nice lighting. To achieve realism in your visualizations, you will have to take care about several other things, which are no more less important than proper setting of your rendering options.
- Try to have your object geometry as clean as possible. Clean unnecessary edges (lines), weld those that are in the same direction, have surfaces properly oriented (always facing a camera), etc. Have your objects in proper scale according to each other as well as according to the real world.
- When using 3D models downloaded from the 3D Warehouse or any other similar website, try to use those that look realistic and correctly modeled. Give yourself time to look for “good” ones. If you cannot find it, try to model it by yourself, instead of having a “bad” one in you project. Non-realistic models (not in scale, the way they are modeled or “bad” textures, etc.) will certainly not lead you to the result you are looking for.
- One of the most important parts of achieving realism in your visualizations is texturing. If you apply textures properly to your objects and use realistic texture images, with special care to its size, you will be half way there to your desired result. You can find many web sites from which you can download nice texture images. I often use “Arroway Textures” or textures downloaded from “SketchUp Texture Warehouse” web site. Most importantly is the size of your texture images, that it is properly scaled to the real world. This can of course result in having huge image textures for some objects, but you can still compensate with the other ones. For example, if you have large surface like parquet floor, where you do not want repeating tiles to be recognized, you will have to use a large texture image. However, if you want ceramic tiles of a certain color on your floor, you could use much smaller texture image, which covers only one tile. Anyway, you should make sure that the size of your texture image is in proper (realistic) scale to the real world.
Note: If you apply materials that have texture images properly scaled to your objects, very often only default rendering options will be enough to get a nice image. If you follow the above mentioned facts, as well as you additionally organizing your projects properly (e.g. in layers, groups, components, etc.), you will find your work in SketchUp easy and you will achieve the desired results with no problems, not to mention that the rendering process will be much easier and faster with a realistic result. WORKFLOW 1. Texturing As explained before, it is necessary to use real world scaled textures in order to achieve realism. It also requires that such materials are properly assigned to different surfaces of any object in your scene. What quite often happens is that 3D models that we use from web sites have incorrect texture mapping or we want to change their default materials. In this case, we often find ourselves having non realistic materials applied. To avoid this problem we will use projected textures. The following example shows how to apply projected materials to the lounge sofa.
As shown in the above images you will continue to apply projected textures to all other objects in your project, which you have downloaded from 3D warehouse which contain wrong texture mapping. For objects with flat surfaces, you apply materials as you are used to in SketchUp, just take good care on the size of textures and be sure they look realistic (e.g. real world scale). The following example shows the carpet texture size, so it looks realistic and has a proper scale for our model.
Notice that this texture image is 1808 x 1200 pixels, even though, the settings in the SketchUp material browser show its size at 63,50 cm x 24,15 cm. It doesn’t matter what the scale is, that you set up in the material browser, as long as it is the correct aspect ratio to the imported texture image. You can scale any texture to whatever size, as long as it looks realistic to you. 2. Lighting After modeling, texturing and setting the Physical camera Still Camera type view, we want to set the desired lighting of our scene. The best way of doing this, is to overwrite all materials with light gray color. White color is to strong and pure white does not exist in the real world. Closest to pure white is crystal-clear snow, but still it is not perfectly white. We will do this by setting V-Ray Global Switches “Override materials” parameter to TRUE, and select “Override color” to something like RGB value of 200.200.200.
By doing this, all the materials in our scene will be overwritten with this color, with exception of those ones that have the “Can be Overridden” parameter set to FALSE. This parameter option will be set in V-Ray material browser, for each particular material. Usually we have to set this parameter to FALSE for all window glass objects, if we want to use a daylight system for lighting the scene. Otherwise, the sun light will not be able to enter our scene through the windows and our scene could become completely dark.
V-Ray uses its default sun for daylight system lighting, but we can also use HDRI images instead. By using HDRI images, we can get even better results for achieving realism of our renders. Notice that this will affect only our scene lighting, as we explained before. You will still have to have proper materials setup as well as apply them correctly. In this particular project, I have used the following HDRI image setup for lighting my scene.
Beside all others, adjusting the following V-Ray parameters should enough to set proper lighting in most of your scenes. You will notice that these parameters work exactly like on any digital photo camera. Therefore, if you have any experience with digital photography it will be easier for you to understand the adjustments and the way they affect lighting in your render. a) Shutter speed – (Value represents a fractions of a second. Therefore, value of 50 for example, will represent 1/50 of a second. This means that your scene will be brighter than if you set this value to 100, as in this case, the shutter on your camera will stay open for a longer period and therefore more light will get into it.) b) Film Speed (ISO) – (Often used as a quick dial for exposure changes in the scene. High numbers will make your scene brighter as lower numbers will make it darker. If we increase its value on digital cameras, our image will suffer from significant amount of noise. Luckily, this is not the case with V-Ray Physical camera. c) F-Number – (This parameter handles/controls the size of your virtual aperture. Small numbers represents a larger aperture (larger opening) in your camera, which in turn allows more light in, that will in turn give us a brighter images. Adjusting these three parameters, you will be able to control the brightness of your rendered image. Remember also that these three options will work as explained only if the Physical Camera “Exposure” parameter is set to TRUE.
The other option that will take into account is the setting of “Color Mapping” type. Each of type that you select will have its own calculation method behind it, and each of them has its own pluses and minuses, depending on what you want to get as a result. Refer to other V-Ray tutorials in order to understand how each offered color mapping type affects your rendering. For this particular project, I used “Reinhard type”. You will notice that by choosing the Reinhard color mapping type, several other parameters become available for adjusting. The two most important ones, which you might want to adjust, are the “Multiplier” and the “Burn value”. “Burn value” will allow you to adjust the value of the brightest area in your scene, and with the “Multiplier” you will be able to control the darkest area. Adjusting these options will enable you to control how bright or dark the brightest and darkest parts of your image will be. Logically if you decrease Burn value, your render will result with less burn in brightest area as well as if you increase its value, your render will have more burn in brightest area of the image. Once we have setup lighting options for our scene, we can try to render the override colors image.
If you are satisfied with the result,you can now un-check “Override materials” option in V-Ray “Global switches” option group and try to render your image again.
3. Render Parameters Setup The following V-Ray options have been used in this particular project, in order to get the final result.
Thanks for reading, hope you guys liked it, it´s always good to share knowledge with you. Mario Goleš